Electrosurgical forceps with energy based tissue division

BACKGROUND

p-00021. Technical Field

p-0003The present disclosure relates to an electrosurgical instrument and method for performing electrosurgical procedures. More particularly, the present disclosure relates to an open or endoscopic bipolar electrosurgical forceps including opposing jaw members which include an energy-based cutting element (e.g., cutting electrode) for energy based tissue division.

p-00042. Background of Related Art

p-0005A forceps is a pliers-like instrument which relies on mechanical action between its jaws to grasp, clamp and constrict vessels or tissue. So-called “open forceps” are commonly used in open surgical procedures whereas “endoscopic forceps” or “laparoscopic forceps” are, as the name implies, used for less invasive endoscopic surgical procedures. Electrosurgical forceps (open or endoscopic) utilize mechanical clamping action and electrical energy to effect hemostasis on the clamped tissue. The forceps include electrosurgical conductive plates which apply the electrosurgical energy to the clamped tissue. By controlling the intensity, frequency and duration of the electrosurgical energy applied through the conductive plates to the tissue, the surgeon can coagulate, cauterize and/or seal tissue.

p-0006Tissue or vessel sealing is a process of liquefying the collagen, elastin and ground substances in the tissue so that they reform into a fused mass with significantly-reduced demarcation between the opposing tissue structures. Cauterization involves the use of heat to destroy tissue and coagulation is a process of desiccating tissue wherein the tissue cells are ruptured and dried.

p-0007Since tissue sealing procedures involve more than simply cauterizing tissue, to create an effective seal the procedures involve precise control of a variety of factors. In order to affect a proper seal in vessels or tissue, it has been determined that two predominant mechanical parameters must be accurately controlled: the pressure applied to the tissue; and the gap distance between the electrodes (i.e., distance between opposing jaw members when closed about tissue).

p-0008Many of the instruments of the past include blade members or shearing members which simply cut tissue in a mechanical and/or electromechanical manner. Other instruments generally rely on clamping pressure alone to procure proper sealing thickness and are often not designed to take into account gap tolerances and/or parallelism and flatness requirements which are parameters which, if properly controlled, can assure a consistent and effective tissue seal.

p-0009In addition, conventional or known tissue sealing reciprocating instruments have cutting mechanisms which are primarily designed to mechanically divide tissue (i.e., knife blade) and do not divide tissue in an electrosurgical fashion.

p-0010Thus, a need exists to develop an electrosurgical instrument which effectively and consistently seals, coagulates or cauterizes tissue and which is selectively configurable to cut tissue in an electrosurgical fashion.

SUMMARY

p-0011The present disclosure relates to a vessel or tissue sealing and dividing instrument which is designed to manipulate, grasp and seal tissue utilizing jaw members which are configured to close about tissue to produce a highly effective tissue seal. The instrument includes a pair of jaw members configured for sealing tissue and an energy-based cutting element attached at two or more pivot points to the jaw members. When the jaw members are open, the cutting element is deployed and the instrument can be used to divide tissue. When the jaw members are closed about tissue and the instrument can be used to seal tissue.

p-0012One embodiment according to the present disclosure relates to an electrosurgical bipolar forceps for sealing and dividing tissue. An electrosurgical bipolar forceps for sealing and dividing tissue is disclosed. The forceps includes one or more shaft members having an end effector assembly disposed at a distal end thereof. The end effector assembly includes two jaw members movable from a first position to a second position wherein the jaw members cooperate to grasp tissue therebetween. Each of the jaw members includes an electrically conductive surface adapted to connect to a first energy source which communicates electrosurgical energy through tissue held therebetween. The forceps also include an energy-based cutting element adapted to connect to a second energy source and disposed between the jaw members. The energy-based cutting element is moveable from a first configuration when said jaw members are in the first position to a second configuration wherein the energy-based cutting element is disposed at an angle between the jaw members.

p-0013Another embodiment according to the present disclosure relates to a method. The method includes the steps of providing an electrosurgical bipolar forceps. The forceps includes two jaw members movable from a first position to a second position wherein the jaw members cooperate to grasp tissue therebetween. Each of the jaw members includes an electrically conductive surface adapted to connect to a first energy source which communicates electrosurgical energy through tissue held therebetween. The forceps also include an energy-based cutting element adapted to connect to a second energy source and disposed between the jaw members. The energy-based cutting element is moveable from a first configuration when said jaw members are in the first position to a second configuration wherein the energy-based cutting element is disposed at an angle between the jaw members. The method also includes the steps of positioning the jaw members in the first position to deploy the energy-based cutting element, supplying electrosurgical energy to the energy-based cutting element, and moving electrosurgical bipolar forceps to position the energy-based cutting element in operative proximity to tissue thereby cutting tissue.

p-0014A further embodiment according to the present disclosure relates to another method. The method includes the steps of providing an electrosurgical bipolar forceps. The forceps includes two jaw members movable from a first position to a second position wherein the jaw members cooperate to grasp tissue therebetween. Each of the jaw members includes an electrically conductive surface adapted to connect to a first energy source which communicates electrosurgical energy through tissue held therebetween. The forceps also include an energy-based cutting element adapted to connect to a second energy source and disposed between the jaw members. The energy-based cutting element is moveable from a first configuration when said jaw members are in the first position to a second configuration wherein the energy-based cutting element is disposed at an angle between the jaw members. The method also includes the steps of positioning the jaw members into the subsequent position wherein the jaw members cooperate to grasp tissue therebetween and communicating electrosurgical energy through tissue held therebetween thereby sealing tissue.

BRIEF DESCRIPTION OF THE DRAWINGS

p-0015Various embodiments of the present disclosure are described herein with reference to the drawings wherein:

p-0016<figref idrefs="DRAWINGS">FIG. 1</figref> is a perspective view of an endoscopic bipolar forceps having a cutting element according to the present disclosure;

p-0017<figref idrefs="DRAWINGS">FIG. 2</figref> is a side, partial internal view of an endoscopic forceps showing a cutting electrode in a deployed configuration according to the present disclosure;

p-0018<figref idrefs="DRAWINGS">FIG. 3A</figref> is a front view of another end effector assembly according to the present disclosure;

p-0019<figref idrefs="DRAWINGS">FIG. 3B</figref> is a front view of another end effector assembly according to the present disclosure;

p-0020<figref idrefs="DRAWINGS">FIG. 4</figref> is a rear, perspective view of the end effector of <figref idrefs="DRAWINGS">FIG. 3A</figref> shown with tissue grasped therein; and

p-0021<figref idrefs="DRAWINGS">FIG. 5</figref> is a perspective view of an open bipolar forceps having a cutting element according to the present disclosure.

DETAILED DESCRIPTION

p-0022Particular embodiments of the present disclosure will be described hereinbelow with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail.

p-0023<figref idrefs="DRAWINGS">FIG. 1</figref> shows an endoscopic vessel sealing bipolar forceps <b>10</b>. Those skilled in the art will understand that the invention according to the present disclosure may be adapted for use with either an endoscopic instrument or an open instrument. It should also be appreciated that different electrical and mechanical connections and other considerations apply to each particular type of instrument, however, the novel aspects with respect to the energy-based cutting element for energy based tissue division are generally consistent with respect to both the open or endoscopic designs. Moreover and as described herein, the various figures show vessel sealin instruments for use with energy-based cutting element, however other instruments may be configured to use the same or similar cutting element, e.g., cauterizing instruments, coagulators, etc.

p-0024In the drawings and in the description which follows, the term “proximal”, refers to the end of the forceps <b>10</b> which is closer to the user, while the term “distal” refers to the end of the forceps which is further from the user.

p-0025<figref idrefs="DRAWINGS">FIGS. 1-4</figref> show the forceps <b>10</b> which is configured to support an effector assembly <b>100</b>. More particularly, forceps <b>10</b> generally includes a housing <b>20</b>, a handle assembly <b>30</b>, a rotating assembly <b>80</b>, and a trigger assembly <b>70</b> which mutually cooperate with the end effector assembly <b>100</b> to grasp, seal and, if required, divide tissue. The forceps <b>10</b> also includes a shaft <b>12</b> which has a distal end <b>14</b> which mechanically engages the end effector assembly <b>100</b> and a proximal end <b>16</b> which mechanically engages the housing <b>20</b> proximate the rotating assembly <b>80</b>.

p-0026The forceps <b>10</b> also includes a plug (not shown) which connects the forceps <b>10</b> to a source of electrosurgical energy, e.g., an electrosurgical generator <b>500</b>, via an electrical cable <b>310</b>. Handle assembly <b>30</b> includes a fixed handle <b>50</b> and a movable handle <b>40</b>. Handle <b>40</b> moves relative to the fixed handle <b>50</b> to actuate the end effector assembly <b>100</b> and enable a user to grasp and manipulate tissue <b>400</b> as shown in <figref idrefs="DRAWINGS">FIG. 2</figref>.

p-0027The end effector assembly <b>100</b> includes a pair of opposing jaw members <b>110</b> and <b>120</b> each having an electrically conductive sealing plate <b>112</b> and <b>122</b>, respectively, attached thereto for conducting electrosurgical energy through tissue <b>400</b> held therebetween. More particularly, the jaw members <b>110</b> and <b>120</b> move in response to movement of the handle <b>40</b> from an open position to a closed position. In open position the sealing plates <b>112</b> and <b>122</b> are disposed in spaced relation relative to one another. In a clamping or closed position the sealing plates <b>112</b> and <b>122</b> cooperate to grasp tissue and apply electrosurgical energy thereto.

p-0028The jaw members <b>110</b> and <b>120</b> are activated using a drive assembly (not shown) enclosed within the housing <b>20</b>. The drive assembly cooperates with the movable handle <b>40</b> to impart movement of the jaw members <b>110</b> and <b>120</b> from the open position to the clamping or closed position. Examples of a handle assemblies are shown and described in commonly-owned U.S. application Ser. No. 10/389,894 entitled “VESSEL SEALER AND DIVIDER AND METHOD MANUFACTURING SAME” and commonly owned U.S. application Ser. No. 10/460,926 entitled “VESSEL SEALER AND DIVIDER FOR USE WITH SMALL TROCARS AND CANNULAS” which are both hereby incorporated by reference herein in their entirety.

p-0029In addition, the handle assembly <b>30</b> of this particular disclosure includes a four-bar mechanical linkage which provides a unique mechanical advantage when sealing tissue between the jaw members <b>110</b> and <b>120</b>. For example, once the desired position for the sealing site is determined and the jaw members <b>110</b> and <b>120</b> are properly positioned, handle <b>40</b> may be compressed fully to lock the electrically conductive sealing plates <b>112</b> and <b>122</b> in a closed position against the tissue. The details relating to the inter-cooperative relationships of the inner-working components of forceps <b>10</b> are disclosed in the above-cited commonly-owned U.S. patent application Ser. No. 10/369,894. Another example of an endoscopic handle assembly which discloses an off-axis, lever-like handle assembly, is disclosed in the above-cited U.S. patent application Ser. No. 10/460,926.

p-0030The forceps <b>10</b> also includes a rotating assembly <b>80</b> mechanically associated with the shaft <b>12</b> and the drive assembly (not shown). Movement of the rotating assembly <b>80</b> imparts similar rotational movement to the shaft <b>12</b> which, in turn, rotates the end effector assembly <b>100</b>. Various features along with various electrical configurations for the transference of electrosurgical energy through the handle assembly <b>20</b> and the rotating assembly <b>80</b> are described in more detail in the above-mentioned commonly-owned U.S. patent application Ser. Nos. 10/369,894 and 10/460,926.

p-0031As best seen with respect to <figref idrefs="DRAWINGS">FIGS. 1-2</figref>, the end effector assembly <b>100</b> attaches to the distal end <b>14</b> of shaft <b>12</b>. The jaw members <b>110</b> and <b>120</b> are preferably pivotable about a pivot <b>160</b> from the open to closed positions upon relative reciprocation, i.e., longitudinal movement, of the drive assembly (not shown). Again, mechanical and cooperative relationships with respect to the various moving elements of the end effector assembly <b>100</b> are further described by example with respect to the above-mentioned commonly-owned U.S. patent application Ser. Nos. 10/369,894 and 10/460,926.

p-0032It is envisioned that the forceps <b>10</b> may be designed such that it is fully or partially disposable depending upon a particular purpose or to achieve a particular result. For example, end effector assembly <b>100</b> may be selectively and releasably engageable with the distal end <b>14</b> of the shaft <b>12</b> and/or the proximal end <b>16</b> of the shaft <b>12</b> may be selectively and releasably engageable with the housing <b>20</b> and handle assembly <b>30</b>. In either of these two instances, the forceps <b>10</b> may be either partially disposable or reposable, such as where a new or different end effector assembly <b>100</b> or end effector assembly <b>100</b> and shaft <b>12</b> are used to selectively replace the old end effector assembly <b>100</b> as needed.

p-0033Since the forceps <b>10</b> applies energy through electrodes, each of the jaw members <b>110</b> and <b>120</b> includes a pair of electrically conductive surfaces <b>112</b>, <b>122</b> respectively, disposed on an inner-facing surface thereof. Thus, once the jaw members <b>110</b> and <b>120</b> are fully compressed about the tissue <b>400</b>, the forceps <b>10</b> is now ready for selective application of electrosurgical energy as shown in <figref idrefs="DRAWINGS">FIG. 4</figref>. In order to seal tissue, the tissue grasped by the jaw members <b>110</b>, <b>120</b> under a specified closure pressure from about 3 kg/cm²to about 16 kg/cm²and the jaw members <b>110</b>, <b>120</b> are designed to maintain a gap from about 0.001 inches to about 0.006 inches. At that point, the electrically conductive surfaces <b>112</b> and <b>122</b> cooperate to seal tissue <b>400</b> held therebetween upon the application of electrosurgical energy. Jaw members <b>110</b> and <b>120</b> also include insulators <b>116</b> and <b>126</b> which together with the outer, non-conductive plates of the jaw members <b>110</b> and <b>120</b> are configured to limit and/or reduce many of the known undesirable effects related to tissue sealing, e.g., flashover, thermal spread and stray current dissipation.

p-0034With reference to <figref idrefs="DRAWINGS">FIGS. 2-3</figref>, an energy-based cutting element or center electrode <b>130</b> is deployable between electrically conductive surfaces <b>112</b>, <b>122</b>, respectively. The cutting element <b>130</b> may be an electrode configured to transmit electrosurgical energy, an ultrasonic probe configured to transmit ultrasonic energy or a thermal blade capable of transmitting heat to the tissue.

p-0035The cutting element <b>130</b> is attached to the jaw members <b>110</b> and <b>120</b> at two pivot points <b>131</b> and <b>132</b> respectively. The pivot points <b>131</b>, <b>132</b> may include attachment mechanisms or mechanical interfaces <b>137</b>, <b>139</b> (e.g., pins, shafts, etc.) which attach the cutting element <b>130</b> to the jaw members <b>110</b>, <b>120</b> allowing the cutting element <b>130</b> to rotate freely thereabout (e.g., pass through holes). The pivot points <b>131</b>, <b>132</b> may also include grooves or guides <b>117</b>, <b>127</b> within the jaw members <b>110</b>, <b>120</b> which allow the ends of the cutting element <b>130</b> to move freely during transitioning between open and close positions of the jaw members <b>110</b>, <b>120</b>.

p-0036It is envisioned that the cutting element <b>130</b> can be shaped in a variety of geometrical configurations to provide an optimal cutting surface. For instance, the cutting element <b>130</b> may have a circular, rectangular, triangular horizontal cross section.

p-0037The pivot points <b>131</b>, <b>132</b> are positioned at opposite ends of jaw members <b>110</b> and <b>120</b>, respectively. More specifically, pivot point <b>131</b> is positioned at a distal end <b>116</b> of the jaw member <b>110</b> and pivot point <b>132</b> is positioned at a proximal end of the jaw member <b>120</b>. The pivots <b>131</b>, <b>132</b> move within groves on guides <b>117</b>, <b>127</b> in jaw members <b>110</b>, <b>120</b> respectively. This configuration allows the cutting element <b>130</b> to be automatically deployed when the jaw members <b>110</b>, <b>120</b> are in open position so that the cutting element <b>130</b> intersects the center plane “C.” It is envisioned that the pivot points <b>131</b>, <b>132</b> may be oriented in a plurality of ways which permit the cutting element <b>130</b> to be deployed at various angles “α” when the jaw members <b>110</b>, <b>120</b> are open. For instance, the pivot point <b>131</b> may be disposed more towards the proximal end of jaw member <b>110</b> to increase the cutting angle the pivot point <b>132</b> may be disposed more towards the distal end of jaw member <b>120</b> depending upon a particular purpose. The cutting angle may also be dependent in the relative opening of the jaw members <b>110</b>, <b>120</b>, i.e., the relative distance between the jaw members <b>110</b>, <b>120</b> when opened.

p-0038As shown in <figref idrefs="DRAWINGS">FIG. 3A</figref>, the electrically conductive surfaces <b>112</b>, <b>122</b> may include electrically conductive plates <b>140</b>, <b>142</b>, <b>144</b>, <b>146</b>. This permits the cutting element <b>130</b> to be attached to the jaw members <b>110</b>, <b>120</b> in an unimpeded fashion, i.e., without contacting the conductive surfaces <b>112</b>, <b>122</b>. It is envisioned that the electrically conductive surfaces <b>112</b>, <b>122</b> may include any number of electrically conductive plates, such as for instance, a single electrically conductive plate <b>148</b>, <b>150</b> disposed on each jaw member <b>110</b>, <b>120</b>, as shown in <figref idrefs="DRAWINGS">FIG. 3B</figref>, or eight plates (not shown), etc. The single electrically conductive plate <b>148</b> may be shaped in a number of forms, such as a “U” shape, a “H” shape. It is also envisioned that the electrically conductive plate <b>148</b> may be oriented in a plurality of ways. In addition, the single conductive plate <b>148</b> may be shaped to substantially match the surface of the jaw members <b>110</b>, <b>120</b> with an opening for the pivot points <b>131</b>, <b>132</b>.

p-0039The ability of the cutting element <b>130</b> to automatically fold and raise as the jaw members <b>110</b>, <b>120</b> are opened and closed respectively, allows the forceps <b>10</b> to have two modes of operation: a sealing mode and a cutting mode. During sealing mode, the jaw members <b>110</b> and <b>120</b> are clamped down in direction F as shown in <figref idrefs="DRAWINGS">FIG. 4</figref> around tissue. The cutting element <b>130</b> folds down and the electrically conductive plates <b>140</b>, <b>142</b>, <b>144</b>, <b>146</b> are energized thereby sealing tissue. Clamping of the jaw members <b>110</b>, <b>120</b> is accomplished by moving the handle <b>40</b> relative to the fixed handle <b>50</b> to actuate the end effector assembly <b>100</b>. The electrically conductive plates <b>140</b>, <b>142</b>, <b>144</b>, <b>146</b> may be selectively energized once the jaw members <b>110</b>, <b>120</b> are closed about tissue. The center electrode <b>130</b> in its folding orientation may be energized when the jaw members are closed to allow the user to selectively ct tissue after the seal has been formed. Alternatively, the center electrode or cutting element <b>130</b> may be energized when the jaw members are closed about tissue without prior sealing. It is envisioned that an alarm (not shown) may be included in this instance to warn the user that the tissue has not been treated prior to separation.

p-0040During an open cutting mode the jaw members <b>110</b> and <b>120</b> are open such that the cutting element <b>130</b> automatically deploys therebetween. As shown in <figref idrefs="DRAWINGS">FIGS. 1-4</figref>, forceps <b>10</b> also includes a trigger <b>70</b> which activates the generator <b>500</b> to supply electrosurgical energy or other types of energy depending on the type of the cutting element <b>130</b> used (e.g., ultrasonic, heat, etc.). The forceps <b>10</b> may be manually pushed toward and into tissue <b>400</b> as shown in <figref idrefs="DRAWINGS">FIG. 2</figref> while the cutting element <b>130</b> is energized, thereby dividing the tissue along the longitudinal axis of the forceps <b>10</b>.

p-0041From the foregoing and with reference to the various figure drawings, those skilled in the art will appreciate that certain modifications can also be made to the present disclosure without departing from the scope of the same. For example and as mentioned above, it is contemplated that any of the various jaw arrangements and cutting elements disclosed herein may be employed on an open forceps such as the open forceps <b>700</b> shown in <figref idrefs="DRAWINGS">FIG. 5</figref>. The forceps <b>700</b> includes an end effector assembly <b>600</b> which is attached to the distal ends <b>516</b><i>a </i>and <b>516</b><i>b </i>of shafts <b>512</b><i>a </i>and <b>512</b><i>b</i>, respectively. The end effector assembly <b>600</b> includes pair of opposing jaw members <b>610</b> and <b>620</b> which are pivotally connected about a pivot pin <b>665</b> and which are movable relative to one another to grasp vessels and/or tissue. Each of the opposing jaw members <b>610</b>, <b>620</b> include electrically conductive surfaces <b>112</b>, <b>122</b> and cutting element <b>130</b> disposed therebetween. When in an open configuration, the cutting element <b>130</b> deployed and the open forceps <b>700</b> may be used for dividing tissue when the cutting element <b>130</b> is selectively energized similar to the endoscopic forceps <b>10</b> described above. The open forceps <b>700</b> may also be used for clamping tissue for sealing, coagulation or cauterization without energizing the cutting element <b>130</b>.

p-0042Each shaft <b>512</b><i>a </i>and <b>512</b><i>b </i>includes a handle <b>515</b> and <b>517</b>, respectively, disposed at the proximal end <b>514</b><i>a </i>and <b>514</b><i>b </i>thereof which each define a finger hole <b>515</b><i>a </i>and <b>517</b><i>a</i>, respectively, therethrough for receiving a finger of the user. Finger holes <b>515</b><i>a </i>and <b>517</b><i>a </i>facilitate movement of the shafts <b>512</b><i>a </i>and <b>512</b><i>b </i>relative to one another which, in turn, pivot the jaw members <b>610</b> and <b>620</b> from an open position wherein the jaw members <b>610</b> and <b>620</b> are disposed in spaced relation relative to one another to a clamping or closed position wherein the jaw members <b>610</b> and <b>620</b> cooperate to grasp tissue or vessels therebetween. Further details relating to one particular open forceps are disclosed in commonly-owned U.S. application Ser. No. 10/962,116 filed Oct. 8, 2004 entitled “OPEN VESSEL SEALING INSTRUMENT WITH CUTTING MECHANISM AND DISTAL LOCKOUT”, the entire contents of which being incorporated by reference herein.

p-0043While several embodiments of the disclosure have been shown in the drawings and/or discussed herein, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.